Built detergent composition

ABSTRACT

Built detergent compositions comprising an organic synthetic detergent and, as a detergency builder, the biodegradable watersoluble salts of a mixture of benzene pentacarboxylic acid and benzene hexacarboxylic acid in a proportion by weight of detergent to builder in the range of 5:1 to 1:20. The watersoluble salts of benzene pentacarboxylic acid and benzene hexacarboxylic acid are present as a mixture in a ratio of from 1:10 to 2:1.

United States Patent [1 1 Connor et al.

[ Oct. 29, 1974 BUILT DETERGENT COMPOSITION [75] Inventors: Daniel S. Connor, Colerain Township, Hamilton County; James E. Thompson, Springfield Township, Hamilton County, both of Ohio [73] Assignee: The Procter & Gamble Company, Cincinnati, Ohio [22] Filed: May 11, 1971 [21 Appl. No.: 142,360

Related US. Application Data [63] Continuation-impart of Ser. No. 879,612, Nov. 24,

1969, abandoned.

[52] US. Cl 252/544, 252/89, 252/132, 252/135, 252/180, 252/541, 252/DIG. 11 [51] Int. Cl Clld 3/20 [58] Field of Search 252/89, 132, 135, 539, 252/558, 544

[56] References Cited UNITED STATES PATENTS 2,264,103 11/1941 Tucker 252/132X Primary Examiner-Leon D. Rosdol Assistant Examinerl-larris A. Pitlick [57] ABSTRACT I Built detergent compositions comprising an organic synthetic detergent and, asa detergency builder, the biodegradable water-soluble salts of a mixture of benzene pentacarboxylic acid and benzene hexacarboxylic acid in a proportion by weight of detergent to,

builder in the range of 5:1 to 1:20. The water-soluble salts of benzene pentacarboxylic acid and benzene hexacarboxylic acid are present as a mixture in a ratio of from 1:10 to 2:1. 1

1 Claim, No Drawings BUILT DETERGENT COMPOSITION BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to a detergent composition which contains an organic water-soluble synthetic detergent and a detergency builder. Such compositions are generally referred to in the art as built detergent compositions. When a large proportion of the detergency builder is used in relation to the detergent, the composition is characterized as a heavy duty composition intended primarily for laundering heavily soiled fabrics which ordinarily comprise a household laundry. Detergent compositions which contain relatively lesser amounts of builder are light-duty compositions intended for lightly soiled fabrics and so-called fine fabrics and woolens.

2. BACKGROUND AND DESCRIPTION OF PRIOR ART The use of detergency builders as adjuncts to organic water-soluble synthetic detergents and the property which some materials have of improving the overall detergency performance of such detergents are well known phenomena. Polyphosphates are the most commonly used builders and within this class alkali metal,

eg, sodium and potassium, polyphosphates and pyrophosphates are most preferred.

ln aqueous solutions, however, polyphosphates are known to hydrolyze to pyrophosphates and orthophosphates. Pyrophosphates have a tendency to form undesirable, insoluble precipitates with water hardness minerals such as calcium and magnesium which tend to deposit on fabrics. In this respect, they are similar to other well-known precipitating builders such as carbonates, soaps and mellitic acid. This latter compound, which is an-essential ingredient in this invention, is described in US. Pat. No. 2,264,103 issued to Nathaniel Beverly Tucker. Mellitic acid (common nominer of benzene hexacarboxylic acid) does perform satisfactory at certain usage levels and water hardness contents. However, built detergent formulations are commonly formulated to be used over a wide part of the country and, oftentimes, over a wide part of the world. Because of this fact, a very broad range of water hardness will be encountered which in itself dictates that a built detergent composition must be effective at both extremes of water hardness contents. Detergent compositions containing a water-soluble salt of mellitic acid as the builder component perform satisfactorily from a nonprecipitating standpoint at normal usage levels in areas where the water hardness content of the water is relatively low. However. where the water is relatively hard, water-insoluble calcium and magnesium salts of mellitic acid are formed which, as stated above, precipitate onto the laundry. The effect of this is that the laundry, even after receiving a rinse, retains the aforementioned precipitates and, as a consequence, has a faded appearance and a chalky feel. Usage of an unduly large amount of a mellitic acid salt-containing detergent composition can be used to obtain satisfactory cleaning, but is objectionable to the average consumer because of economical reasons.

As a result of the inability of mellitic acids salts to perform properly in hard water areas, its inclusion into a detergent composition formulated for a wide area distribution has been necessarily avoided.

In addition to the above deficiency of the polyphosphates, some concern has been expressed that certain algae in bodies of water resort to phosphorouscontaining materials for nutritional value. Phosphorusfree builder compounds, though, such as mellitic acid would be free of such criticism.

SUMMARY OF THE INVENTION It has now been discovered that a mixture of the water-soluble salts of benzene pentacarboxylic acid and benzene hexacarboxylic acid unexpectedly meets the foregoing requirements for an effective phosphorus-free substantially biodegradable detergency builder that can be effectively used in detergent compositions useful over a wide range of water hardnesses.

Accordingly, the present invention relates to built detergent compositions, consisting essentially of: (a) an organic water-soluble synthetic detergent; and (b) as a detergency builder, the substantially biodegradable phosphorus-free water-soluble saltsof a mixture of benzene pentacarboxylic acid and benzene hexacarboxylic acid in. the proportion by weight of from l:l0 to 2 :1, respectively, and wherein the proportion by weight of the detergent to the detergency builder is from 5:1 -to 1:20. The water-soluble cation of the polycarboxylic acids can be alkali metal such as sodium or potassium, ammonium or substituted ammonium such as tetraalkylammonium in which the alkyl group is methyl, ethyl, propyl, or isopropyl.

SPECIFIC DESCRIPTION OF THE INVENTION The preferred biodegradable builders are sodium or potassium salts of benzene penta-and hexacarboxylic acid.

Benzene pentacarboxylic acid, having the formula C H OW and molecular weight of 298, has the following formula:

HOOC OOOH HOOC -COOH boon This acid is available commercially as colorless crystals having a melting point of 228C. Additional properties of the acid and the preparation thereof is found on page 329 of the Dictionary of Organic Compounds (Heilbron-Oxford University Press, I965 Volume I, (A-Chlop). I

Benzene hexacarboxylic acid is commonly referred I to as mellitic acid. Mellitic acid, C I- 50 molecular weight 342.1, has the following formula Thiscommercially available acid has colorless needles having a meltingpoint of 287C. which are soluble in water or alcohol. lts aluminum salt occurs in brown coal as honeystoneThis acid is further described together with properties and preparations on Page 2067 of Dictionary of Organic Compounds (Heilbron Oxford University Press, 1965), Volume 4, (.l-Phloi).

Unexpectedly it has been found that a mixture of the benzene pentaand hexacarboxylic acid salts when incorporated into a detergent composition results in a dc tergent composition that is satisfactorily useful in waters possessing a broad range of water hardness contents. In particular, ,a detergent composition containing a mixture of the above mentioned polycarboxylate acid salts performs satisfactorily in relatively hard water, while another detergent composition containing the same totalamount of builder in the form of a benzene hexacarboxylic acid salt does not perform satisfactorily at the same useage level. By not performing satisfactorily is meant that clothing continually washed with a solely benzene hexacarboxylic acid salt built detergent composition possesses a rough chalky feel and appears to be faded. Actually the faded appearance is primarily due to the deposition of a lightly colored precipitate from the wash water onto the clothing. This precipitate persists even after rinsing with water.

For some reason not fully understood, the addition of a benzene pentacarboxylic acid salt to the benzene hexacarboxylic acid salt significantly decreases the amount of precipitate that will form from a wash solution containing the same. It has been found that a mixture of benzene pentacarboxylic acid salt to benzene hexacarboxylic acid salt of from 1:10 to 2:1 ona weight basis provides a builder mixture that when formulated into a detergent composition at a level hereinafter disclosed is eminently satisfactory for a wide range of washing conditions. A ratio below 1:10 does provide some benefit but is not significant enough to be observed by most consumers. A mixture ratio above 2: 1 is avoided in part because no added advantages accrue with respect to the prevention or modification of precipitates. Additionally, the benzene hexacarboxylic acid salt is a more effective cleaning component with respect to removing soil from laundry than is the benzene pentacarboxylic acid salt. Therefore, mixture ratios above 2:1 of the benzene pentato benzene hexacarboxylic acid salt adversely have an effect on the aforementioned cleaning power. The aforementioned mixture ratio of 1:10 to 2:] possesses the best performance properties with respect to precipitates prevention and cleaning ability. Preferably a mixture ratio of 1:5 to 1:1 on a weight basis is used in this invention.

The organic water-soluble synthetic detergent compounds with which the biodegradable builder compounds ofthe present invention can be used include anionic, nonionic, zwitterionic, or ampholytic detergents or mixtures of such classes of detergents. Each of these classes is illustrated below.

A. Anionic Soap and Non-Soap Synthetic Detergents This class of detergents includes ordinary alkali metal soaps such as the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms and preferably from about to about carbon atoms. Suitable fatty acids can be obtained from natural sources such as, for instance, from plant oranimal esters (e.g., palm oil, co-

conut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils,. grease,lard, and mixtures thereof). The fatty acids also can be synthetically prepared (e. g., by the oxidation of petroleum, or by hydrogenation or carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Napthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

This class of detergents also includes water-soluble salts, particularly the alkali metal salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester radical. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Examples of this group of synthetic detergents which form a part of the preferred built detergent compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g. those of the type described in US. Pat. Nos. 2,220,099 and 2,477,383 (especially valuable are linear straight chain alkyl benzene sulfonates in which the average of the alkyl groups is about 13 carbon atoms abbreviated hereinafter as C LAS); sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g. tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain about 8 to about 12 carbon atoms.

Anionic phosphate sulfactants are also useful in the present invention. These are surface active materials having substantial detergent capability in which the anionic solubilizing group connecting hydrophobic moieties is an oxy acid of phosphorus. The more common solubilizing groups, of course, areSO H, -SO -,H, and CO H. Alkyl phosphate esters such as (R-0) PO H and ROPO H in which R represents an alkyl chain containing from about .8 to about 20 carbon atoms are useful.

These esters can be modified by including in the molecule from one to about alkylene oxide units, e.g., ethylene oxide units. Formulae for these modified phosphate anionic detergents are it; which R represents an alkyl group containing from about 8 to carbon atoms, or an alkylphenyl group in which the alkyl group contains from about 8 to 20 carbon atoms, and M represents a soluble cation such as hydrogen, sodium, potassium, ammonium or substituted ammonium; and in which n is an integen from 1 to about 40.

Another class of suitable anionic organic detergents particularly useful in this invention includes salts of 2-acyloxy-alkane-l-sulfonic acids. These salts have the formula (iJfIiRz where R, is alkyl of about 9 to about 23 carbon atoms (forming with the two carbon atoms an alkane group); R is alkyl of l to about 8 carbon atoms; and M is a saltforming radical.

The salt-forming radical M in the hereinbefore described structural formula is a water-solubilizing cation and can be, for example, an alkali metal cation (e.g. sodium, potassium, lithium), ammonium or substitutedammonium cation. Specific examples of substituted ammonium cations include methyl-, dimethyl-, and trimethylammonium cations and quaternary ammonium cations such as tetramethyl-ammonium and dimethyl piperdinium cations and those derived from alkylamines such as ethylamine, diethyl-amine, triethylamine, mixtures thereof, and the like.

Specific examples of B-acyloxy-alkane-l-sulfonates, or alternatively 2-acyloxy-alkane-l-sulfonates, utilizable herein to provide superior cleaning levels under substantially neutral washing conditions include the sodium salt of 2-acetoxy-tridecane-l-sulfonic acid; the potassium salt of 2-propionyloxy-tetradecane-lsulfonic acid; the lithium salt of 2-butanoyloxytetradecane-l-sulfonic acid; the sodium salt of 2- pentanoyloxy-pentadecane-l-sulfonic acid; the sodium salt of 2-acetoxy-hexadecane-l-sulfonic acid; the potassium salt of 2-octanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of 2-acetoxy-heptadecane-lsulfonic acid; the lithium salt of 2-acetoxy-octadecanel-sulfonic acid; the potassium salt of Z-acetoxynonadecane-l-sulfonic acid; the sodium salt of Z-acetoxy-uncosane-l-sulfonic acid; the sodium salt of 2-propionyloxy-docosane-l-sulfonic acid; the isomers thereof.

Preferred B-acyloxy-alkane-l-sulfonate salts therein are the alkali metal salts of ,B-acetoxy-alkanel -sulfonic acids corresponding to the above formula wherein R is an alkyl of about l2 to about 16 carbon atoms, these salts being preferred from the standpoints of their excellent cleaning properties and ready availability.

Typical examples of the above described B-acetoxy alkanesulfonates are described in the le'terature: Belgium Pat. No. 650,323 issued July 9, 1963, discloses the preparation of certain 2-acyloxy alkanesulfonicv acids. Similarly, U.S. Pat.'Nos. 2,094,451 issued Sept. 28, 1937, to Guenther et al., and 2,086,215 issued July 6, 1937 to DeGroote disclose certain salts of ,B-acetoxy alkanesulfonic acids. These references are hereby incorporated by reference.

A preferred class of anionic organic detergents are the B-alkyloxy alkane sulfonates. These compounds have the following formula:

where R, is a straight chain alkyl group having from 6 to 20 carbon atoms, R is a lower alkyl group having from 1 to 3 carbon atoms, and M is a salt-forming radical hereinbefore described.

Specific examples of B-alkyloxy alkane sulfonates or alternatively 2-alkyloxy-alkane-l-sulfonates, utilizable herein to provide superior cleaning and whitening levels under household washing conditions include potassium B-methoxydecanesulfonate,

sodium B-methoxy-tridecanesulfonate,

potassium ,8-ethoxytetradecylsulfonate,

sodium B-isopropoxyhexadecylsulfonate,

lithium ,Bt-butoxytetradecylsulfonate,

sodium B-methoxyoctadecylsulfonate, and

ammonium ,Bn-propoxydodecylsulfonate.

Other synthetic anionic detergents useful herein are alkyl ether sulfates. These materials have the formula RO(C H O),SO M wherein R is alkyl or alkenyl or about 10 to about 20 carbon atoms, x is l to 30, and M is a salt-forming cation defined hereinbefore.

The alkyl ether sulfates of the present invention are condensation products of ethylene oxide and monohydric alcohols having about 10 to about 20 carbon atoms. Preferably, R has 14 to 18 carbon atoms. The alcohols can be derived from fats, e.g., coconut oil or tallow, or can be synthetic. Lauryl alcohol and straight chain alcohols derived from tallow are preferred herein. Such alcohols are reacted with l to 30, and especially 6, molar proportions of ethylene oxide and the resulting mixture ofmolecular species, having, for example, an average of 6 moles of ethylene oxide per mole of alcohol, is sulfated and neutralized.

Specific examples of alkyl ether sulfates of the present invention are sodium coconut alkyl ethylene glycol ether sulfate; lithium tallow alkyl triethylene glycol ether sulfate; and sodium tallow alkyl hexaoxyethylene sulfate.

Preferred herein for reasons of excellent cleaning properties and ready availability are the alkali metal coconutand tallow-alkyl oxyethylene ether sulfates having an average of about I to about 10 oxyethylene moieties. The alkyl ether sulfates of the present invention are known compounds and are described in Pat. No. 3,332,876 to Walker (July 25, 1967) incorporated herein by reference.

Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are the reaction product of fatty acids esteritied with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of methyl tauride in which the fatty acids, for example, are derived from coconut oil. Other an ionic synthetic detergents of this variety are setforth in Pat. Nos. 2,486,921; 2,486,922; and 2,396,278.

Additional examples of anionic, non-soap, synthetic detergents, which come within the terms of the present invention, are the compounds which contain two anionic functional groups. These are referred to as dianionic detergents. Suitable di-anionic detergents are the disulfonates, disulfates, or mixtures thereof which may be represented by the following formulae:

where R is an acyclic aliphatic hydrocarbyl group having 15 to 20 carbon atoms and M is a water-solubilizing cation, for example, the C to disodium 1,2- alkyldisulfates, C to C dipotassium-l,2-alkyldisulfonates or disulfates, disodium l,9-hexadecyl sidulfates, C, to C disodium-l,2-alkyldisulfonates, disodium l,9stearydisulfates and 6,l0-octadecyldisulfates.

The aliphatic portion of the disulfates or disulfonates is generally substantially linear, desirable, among other reasons, because it imparts desirable biodegradable properties to the detergent compound.

The water-solubilizing cations include the customary cations known in the detergent art, i.e., the alkali metals, and the alkaline earth metals, as well as other metals in group "A, B, lllA, [VA and [VB of the Periodic Table except for Boron. The preferred watersolubilizing cations are sodium or potassium. These dianionic detergents are more fully described in British Letters Pat. No. 1,151,392 which claims priority on an application made in the US. (No. 564,556) on July 12, 1966.

Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of methyl tauride in which the fatty acids, for example, are derived fron coconut oil. Other anionic synthetic detergents of this variety are set forth in US. Pat. Nos. 2,486,921, 2,486,922; and 2,396,278.

Still other anionic synthetic detergents include the class designated as succinamates. This class includes such surface active agents as disodium N- octadecylsulfo succinamate; tetrasodium N-(l,2- dicarboxyethyl)-N-octadecyl-sulfo-succinamate; diamyl ester of sodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid; dioxtyl ester of sodium sulfosuccinic acid.

Other suitable anionic detergents utilizable herein are olefin sulfonates having about 12 to about 24 carbon atoms. The term olefin sulfonates is used herein to mean compounds which can be produced by the sulfonation of a-olefin by means of uncomplexed sulfur trioxide, followed by neutralization of the acid reaction mixture in conditions such that any sultones which have been formed in the reaction are hydrolyzed to give the corresponding hydroxy-alklanesulfonates. The sulfur trioxide may be liquid or gaseous, and is usually, but not necessarily, diluted by inert diluents, for example by liquid SO chlorinated hydrocarbon, etc., when used in the liquid form, or by air, nitrogen, gaseous S0 etc., when used in the gaseous form.

The a-olefins from which the olefin sulfonates are derived are mono-olefins having 12 to 24 carbon atoms, preferably 14 to 16 carbon atoms. Preferably, they are straight chain olefins. Examples of suitable l-olefins include l-dodecene; l-tetradecene; l-hexadecene; loctadecene; l-eicosene and l-tetracosene.

In addition to the true alkene sulfonates and a proportion of hydroxy-alkanesulfonates, the olefin sulfonates can contain minor amounts of other materials, such as alkene disulfonates depending upon the reaction conditions, proportions of reactants, the nature of the starting olefins and impurities in the olefin stock and side reaction during the sulfonation process.

A specific anionic detergent which has also been found excellent for use in the present invention is described more fully in the Pat. No. 3,332,880 of Phillip F. Pflaumer and Adriaan Kessler, issued July 25, 1967, titled Detergent Composition, the disclosure of which is herein incorporated by reference.

B. Nonionic Synthetic Detergents Nonionic synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic." These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 5 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or

nonene, for example.

2. Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40 to about percent polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 and 3,000, are satisfactory.

3. The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from l to 14 carbon atoms.

4. Nonionic detergents include nonyl phenol condensed with either about or about 30 moles of ethylene oxide per mole of phenol and the condensation products of coconut alcohol with an average of either about 5.5 or about moles of ethylene oxide per mole of alcohol and the condensation product of about 15 moles of ethylene oxide with one mole of tridecanol.

Other examples include dodecylphenol condensed with 12 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 15 moles of ethylene oxide per mole of phenol; dodecyl mercaptan condensed with l0 moles of ethylene oxide per mole of mercaptan; bis-(N-2-hydroxyethyl) lauramid; nonyl phenol condensed with moles of ethylene oxide per mole of nonyl phenol; myristyl alcohol condensed with 10 moles of ethylene oxide per mole of myristyl alcohol; lauramide condensed with 15 moles of ethylene oxide per mole of lauramide; and di-isooctylphenol condensed with 15 moles of ethylene oxide.

(5) A detergent having the formula R'R R N O (amine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each R and R" are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms;

Specific examples of amine oxide detergents include: dimethyldodecylamine oxide, dimethyltetradecylamine oxide, ethylmethyltetradecylamine oxide, cetyldimethylamine oxide, dimethylstearylamine oxide, cetylethylpropylamine oxide, diethyldodecylamine oxide, diethyltetradecylamine oxide, dipropyldodecylamine oxide, bis-(Z-hydroxyethyl)dodecylamine oxide, bis- (2-hydroxyethyl )-3-dodecoxyl -hydroxypropylamine oxide, (2-hydroxypropyl)methyltetradecylamine oxide, dimethyloleyamine oxide, dimethyl-(2- hydroxydodecyl)amine oxide, and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.

6. A detergent having the formula R R R"P O (phosphine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each of R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.

Specific examples of the phosphine oxide detergents include: dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, cetyldimethylphosphine oxide, dimethylstearylphosphine oxide, cetylethylpropylphosphine oxide, diethyldodecylphosphine oxide, diethyltetradecylphosphine oxide, dipropyldodecylphosphine oxide, bis- (hydroxymethyl )dodecylphosphine oxide, bis-( 2- hydroxyethyl )-dodecylphosphine oxide, (2- hydroxypropyl )methyltetradecylphosphine oxide,

dimethyloleylphosphine oxide, and dimethyl-(2- hydroxydodecyl)phosphine oxide and the corresponding decyl, hexadecyl, and octadecyl homologs of the above compounds.

7. A detergent having the formula (sulfoxide detergent) where R is an alkyl radical containing from about 10 to about 28 carbon atoms, from 0 to about 5 ether linkages and from O to about 2 hydroxyl substituents at least one moiety of R being an alkyl radical containing 0 ether linkages and containing from about 10 to about 18 carbon atoms, and wherein R is an alkyl radical containing from 1 to 3 carbon atoms and from one to two hydroxyl groups: octadecyl methyl sulfoxide, dodecyl methyl sulfoxide, tetradecyl methyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-methoxytridecyl methyl sulfoxide, 3-hydroxy-4- dodecoxybutyl methyl sulfoxide, octadecyl 2- hydroxyethyl sulfoxide, dodecylethyl sulfoxide.

C. Ampholytic Synthetic Detergents (dodecylamino)propanel -sulfonate, sodium 2- dodecylamino )ethyl sulfate, sodium 2- (dimethylamino )octadecanoate, disodium 3-( N- carboxymethyldodecylamino )-propanel -sulfonate,

disodium octadecyl-iminodiazetate, sodium 1- carboxymethyl-2-undecyl-imidazole, and sodium N,N- bis(2-hydroxyethyl)-2-sulfato3-dodecoxypropylamine.

D. Zwitterionic Synthetic Detergents Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium and phosphonium or tertiary sulfonium compounds, in which the cationic atom may be part of a heterocyclic ring, and in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 3 to 18 carbon atoms, and at least one aliphatic substituent contains an anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are 3- (N,N-dimethyl-N-hexadecyl-ammonio)-2- hydroxypropanel -sulfonate, 3-( N,N-dimethyl-N- hexadecylammonio )-propanel -sulfonate, 2-( N,N- dimethyl-N-dodecylammino)acetate, 3-(N,N-dimethyl N-dodecylammonio)propionate, 2-(N,N-dimethyl-N- octadecylammonio)-ethyl sulfate, 2-(trimethylammonio)ethyl dodecylphosphonate, ethyl 3-(N,N- dimethyl-N-dodecylammonio)propylphosphonate, 3- (P,P-dimethyl-P-dodecylphosphonio )-propanel sulfonate, 2-(S-methyl-S-terthexadecylsulfonio )ethanel -sulfonate, 3-( S-methyl-S- dodecylsulfonio)propionate, sodium 2-(N,N-dimethyl- N-dodecylammonio)ethyl phosphonate, 4-(S-methyl- S-tetradecylsulfonio)butyrate, l-(2-hydroxyethyl)-2- 111 undecylimidazolium-l-acetate, 2-(trimethylammonio)octtadecanoate, and 3-(N,N-bis(2-hydroxyethyl)-N- octodecylammonio)-2-hydroxypropanel sulfonate. Some of these detergents are described in the following Pat. Nos: 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332.

A detergent composition prepared according to the present invention contains as essential ingredients (a) a detergent ingredient and (b) a builder ingredient. In simplest terms, a composition can contain a single detergent compound and the biodegradable builder mixture of benzene pentaand hexacarboxylic acid salts. On the other hand, it frequently is desirable to formulate a detergent compositon in which the detergent ingredient consists of composition of detergent compounds selected from the foregoing classes. Thus, for example, the active ingredient can consist of a mixture of two or more anionic detergents; or a mixture of an anionic detergent and a nonionic detergent; or, by way of another example, the active detergent can be a ternary mixture of two anionic detergents and a zwitterionic detergent.

The discovery of the excellent and unexpected biodegradability characteristics of the benzene hexacarboxylic acid, i.e., mellitic acid, were made by employing the procedures described by J. E. Thompson and J. R. Duthie in an article titled The Biodegradability and Treatability of NTA published in the Journal of Water Pollution Control Federation, February, 1968, Part 1, pp. 3063 19. A more complete description appears in Ludzack, F. J. Schaffer, R. T., Bloomhuff, R. N., and Ettinger, M. 8., "Biochemical Oxidation of Some Commercially lmportant Organic Cyanides." Sewage and Industrial Wastes, 31, l, 33 (Jan. 1959), and Ludzack, F. J., and Ettinger, M. B., Biodegradability of Organic Chemicals Isolated from Rivers. Proceedings 18th Ind. Waste Conf., Purdue Univ., Ext. Ser. 115, 278 (1964).

According to these procedures, in the process of biodegradation an organic molecule such as mellitic acid is broken down enzymatically into simpler substances. For materials containing carbon and hydrogen the theoretical ultimate end products are CO water and metabolites. It is possible to measure the extent of degradation of mellitic acid by comparing the amount of oxygen utilized and the actual amount of CO produced to the appropriate calculated stoichiometric values. These tests surprisingly indicated essentially complete degradation of mellitic acid.

Similarly, the same tests indicate that benzene pentacarboxylic acid is essentially completely degradable.

The present invention can find useful application by practicing a partial replacement of the biodegradable benzene pentaand hexacarboxylic acid salt mixture for traditional, commonly used detergency builders. Thus, for example, the portion of the complete detergent formulation that functions as a builder can likewise be composed of a mixture of builder compounds. For example, the substantially biodegradable builder compounds described herein can be mixed together with other water-soluble inorganic alkaline builder salts such as sodium tripolyphosphate or potassium pyrophosphate or water-soluble organic builder salts such as watersoluble salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethane-l-hydroxy-l, 1- diphosphonic acid. Still further, the builder component of a complete formulation can consist of ternary mixtures of these several types of builder compounds. In this way, it is possible to obtain a balance between the mixture of the biodegradable salts of benzene pentaand hexacarboxylic acid and such builders as sodium tripolyphosphate and the like.

Water-soluble inorganic alkaline builder salts which can be used in this invention in combination with the mixture of the biodegradable salts of benzene pentaand hexacarboxylic acid are alkali metal carbonates,

borates, phosphates, polyphosphates, bicarbonates and silicates. Ammonium and substituted ammonium salts of these materials can also be used. Specific examples of suitable salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium and potassium pyrophosphate, sodium and ammonium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium orthophosphate and potassium bicarbonate.

Examples of suitable organic alkaline detergency builder salts are: (1 Water-soluble aminopolycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetates, nitrilotriacetates and N-(2-hydroxyethyl)- nitrilodiacetates; (2) Water-soluble salts of phytic acid, e.g., sodium and potassium phytates See Pat. No. 2,739,942; (3) Water-soluble, polyphosphonates, including specifically, sodium, potassium and lithium salts of ethane-l-hydroxy-l,l-diphosphonic acid, sodium, potassium and lithium salts of methylene diphosphonic acid, sodium, potassium and lithium salts of ethylene diphosphonic acid, and sodium, potassium and lithium salts of ethane-1 ,1 ,2-triphosphonic acid. Other examples include the alkali metal salts of ethane-2- carboxy-l l -diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethanel-hydroxy-l ,l,2-t riphosphonic acid, ethane-Z-hydroxy- 1,1,2-triphosphonic acid, propane-l ,1 ,3,3-tetraphosphonic acid, propane-1,l,2,3-tetraphosphonic acid, and propane-l,2,2,3-tetraphosphonic acid; (4) Watersoluble salts of polycarboxylate polymers and copolymers as described in the copending application of Francis L. Diehl, application Ser. No. 269,359, filed Apr. 1, 1963, now Pat. No. 3,308,067. Specifically, a detergent builder material comprising a water-soluble salt of a polymeric aliphatic polycarboxylic acid having the following structural relationships as to the position of the carboxylate groups and possessing the following prescribed physical characteristics: (a) a minimum molecular weight of about 350 calculated as to the acid form; (b) an equivalent weight of about to about calculated as to acid form; (c) at least 45 mole percent of the monomeric species having at least 2 carboxyl radicals separated from each other by not more than 2 carbon atoms; (d) the site of attachment of the polymer chain of any carboxyl-containing radical being separated by not more than 3 carbon atoms along the polymer chain from the site of attachment of the next carboxylcontaining radical. Specific examples are polymers of itaconic acid, aconitic acid, maleic acid, mesaconic acid, fumaric acid, methylene malonic acid, and citraconic acid and copolymers with themselves and other compatible monomers such as ethylene; and (5) mixtures thereof.

Mixtures of organic and/or inorganic builders can be used in combination with the builder mixture of the present invention and are generally desirable. One such auxiliary mixture of builders is disclosed In Pat. No. 3,392,121, e.g., ternary mixtures of sodium tripolyphosphate, sodium nitrilotriacetate and trisodium ethane- 1 -hydroxy-l ,l-diphosphonate. The above described builders can also be utilized singly in this invention.

ln addition, other builders can be used satisfactorily such as the water-soluble salts of citric acid, pyromellitic acid, oxydiacetic acid, and oxydisuccinic acid.

It is preferred to practice the present invention with compositions in which the proportion by weight of detergent to builder mixture is in the range of 2:1 to 1:10.

As a result of the present invention, it is possible to provide a complete substantially biodegradable built detergent composition by selecting a biodegradable detergent from those mentioned above and combining it with the biodegradable builder compounds of the present invention in the proportion described above. An illustrative and preferred embodiment is a biodegradable built detergent composition consisting essentially of (A) a detergent selected from alkali metal straightchain alkyl benzene sulfonate, the alkyl group having from 8 to 24 carbon atoms, preferably 8 to 18, and an alkali metal olefin sulfonate having 8 to 24 carbon atoms, preferably 8 to 18, and (B) as a detergency builder, the biodegradable phosphorus-free watersoluble alkali metal salts of the benzene pentaand hexacarboxylic acid mixture, the proportion by weight of said detergent to said builder mixture being in the range of 5:1 to 1:20, and preferably2:l to 1:10. The preferred detergents are sodium B-methoxy hexadecane sulfonate, sodium salt of the sulfonation product of the condensation product of one mole of tallow alcohol with three moles of ethylene oxide, sodium dodecyl benzene sulfonate, sodium tridecyl benzene sulfonate, and sodium dodecene-l-sulfonate, sodium tetradecene-l-sulfonate, and sodium hexadecene-lsulfonate. Sodium salt is the preferred salt of the benzene pentaand hexacarboxylic acids.

The built detergent compositions of the present invention can be formulated and prepared into any of the several commercially desirable solid and liquid forms including, for example, granules, flakes, tablets, and water-based and alcohol-based liquid detergents, and the like. A special embodiment of this invention is a built liquid detergent composition containing a detergent and a builder mixture is the by weight ratio (detergent to builder mixture) of 2:1 to about 1:5; preferably 2:1 to about 1:3. Potassium salts are especially useful in liquid formulations due to the increased solubility characteristics of potassium over sodium.

The built detergent compositions of the present invention perform at their maximum level in a washing solution which has a pH in the range of from about 8 to about 12. Within this broad range, it is preferred to operate at a pH of from about 8.5 to 11. The detergent and the builder mixture can be neutralized to a degree sufficient to insure that this pH prevails in any washing solution. If desired, other alkaline materials can be added to the complete formulation to provide for any pH adjustments desired. A preferred embodiment is to have the detergent composition whether in solid or liquid form provide a pH in the aforementioned ranges at the usual recommended usage levels.

ln a finished detergent formulation, there can be present other materials which make the product more effective or more aesthetically attractive. The following are mentioned only by way of example. A water-soluble sodium carboxymethyl cellulose can be added in minor amounts to inhibit soil redeposition. Tarnish inhibitors such as benzotriazole or ethylenethiourea can also be added in amounts up to about 3 percent. Fluorescers, and brighteners,.enzymes, perfumes, coloring agents,

while not per se essential in the compositions of this inv vention, can be added in minor amounts. As already mentioned, an alkaline material or alkali such as sodium or potassium hydroxide can be added as supplementary pH adjusters. Other usual additives include sodium sulfate, sodium carbonate, water, and the like. Corrosion inhibitors are also frequently used. Watersoluble silicates are highly effective corrosion inhibi tors and can be added if desired at levels of from about 3 to about 8 percent by weight of the total composition. Alkali metal, preferably potassium and sodium silicates, are preferred having a weight ratio of SiO :M O of from about 1.0:1 to 2.8: 1. (M refers to sodium or potassium). Sodium silicate having a ratio of SiO :Na O of from about 1.621 to 2.45:1 is especially preferred.

In the embodiment of this invention which provides for a built liquid detergent, a hydrotrope is desirable. Suitable hydrotropes are water-soluble alkali metal salts of toluenesulfonate, benzenesulfonate, and xylenesulfonate. Preferred hydrotropes are potassium or sodium toluenesulfonates. The hydrotrope salt may be added at levels up to about 12 percent. While a hydrotrope will not ordinarily be found necessary, it can be added, if so desired, for any reason such as to function as a solubilizing agent and to produce a product which retains its homogeneity at a low temperature.

The following compositions, in which the precentages are by weight, will serve to illustrate, but not limit, the invention. Each of the compositions in the following Examples give in solution a pH within the desired range of from about 8 to about 12.

EXAMPLE A A granular built detergent composition according to this invention has the following formulation:

Sodium alkyl benzene sulfonate in which the alkyl is a straight chain dodecyl radical Pentasodium salt of benzene pentacarboxylic acid Pentasodium salt of benzene hexacarboxylic acid Sodium sulfate Sodium silicate (ratio of siomt o of 2:1

1071 Water This heavily built detergent composition is especially valuable for laundering heavily soiled clothes.

The straight chain dodecyl benzene sodium sulfonate in the preceding composition can be replaced on an equal weight basis by either branched chain sodium dodecyl benzene sulfonate, sodium tallow alkyl sulfate, sodium coconut oil alkyl sulfate, sodium olefin sulfonate as described in the specification derived from alpha olefins having an average of 14 carbon atoms in the molecule, or a mixture of straight chain dodecyl benzene sodium sulfonate and sodium tallow alkyl sulfate on an equal weight basis.

EXAMPLE B Another effective granular detergent composition has the following formulation:

4% Straight chain sodium tridecyl benzene sulfonate 47: Sodium tallow alkyl sulfate (anionic detergent) In this Example, the total active detergent of 10 percent can be totally the nonionic species. In addition, the 2 percent dodecyl methyl sulfoxide can be replaced by the product of a condensation reaction between dodecyl phenol and 5 moles of ethylene oxide per mole of dodecyl phenol, or by 3-(dodecyldimethylammonio)-2-hydroxy propane-l-sulfonate.

The sodium salts of the builders can be added as the salt or they can be present as the free acid neutralized in situ to the salt form.

The effectiveness of the mixture of sodium salts of the benzene pentaand hexacarboxylic acids builder was demonstrated by a detergency test referred to as a fabric softness/deposition test. This test generally involves a procedure of washing laundry with the detergent composition to be tested.

The laundry pieces are washed, rinsed, graded, and the cycle is repeated several times. Grading of fabric deposition is made on a scale of to 5 where 0 represents no visual precipitate deposit. Softness is also reflected in this grading in that the deposit of precipitates on the laundry samples will adversely affect its feel.

EXAMPLE C Composition Pentasodium salt of benzene pcntacarboxylic acid 1 .57:

Hexasodium salt of benzene hexacarboxylic acid 12.57:

Sodium TE;,S (sulfonation product of the 13.8%

condensation product ofone mole oftallow alcohol with 3 moles ol'ethylene oxide) Sodium LAS (linear C, alkyl benzene sulfonate) 11.2%

Sodium silicate (SiO aNa O ratio 2.0) H1071 Sodium sulfate 25.07!

Balance (water) 15.071

A commercially available automatic washer was filled with 16 gallons of water having a temperature of 100F and hardness of 14 grains. One and one-fourth cups of the above detergent composition was next added. The contents of the washer was agitated for 30 seconds to dissolve the detergent composition. Thereafter, 2 pounds of ordinary soiled laundry plus a dark colored cotton wash cloth were added and washed for 6 minutes. The ordinary soiled laundry in addition to the wash cloth was used in this example as a source of soil and in order to give a full load. For purposes of this example, the originally soiled laundry was not evaluated at the end of the wash cycles. After a cold rinse, the originally soiled laundry and wash cloth were spun. removed, and line dried.

This procedure was repeated 9 times and then the wash cloth evaluated. No fading effect" was noticeable, thereby indicating that enough precipitates were not deposited on the wash cloth to change the color thereof. A rating of 1 was recorded for the fabric deposition test. This compared favorably with results obtained with a commercially available laundry detergent.

Mixture ratios of the sodium salt of benzene pentacarboxylic acid to the sodium salt of the benzene hexacarboxylic acid of 1:10 and of 2:] when substituted for the 1:1 mixture in the above examples at the same total builder level gives substantially similar results.

EXAMPLE D To show the unexpected advantage that a mixture of salts of benzene pentaand hexacarboxylic acids has over the benzene hexacarboxylicacid salt. the following detergent composition was tested under the same washing conditions as in Example C:

Sodium salt of benzene hexacarboxylic acid After 10 washings the softness of the wash cloth of this example was comparable to the wash cloth washed with the composition of Example C. Softnessis very difficult to measure and the full difference in softness between the mixture built composition of this invention and the mellitic acid salt-built composition could not be expected to be noticeably different after only 10 washings. However, the originally dark colored wash cloth of this example was noticeably lighter in color indicating that precipitates had been deposited. The fabric deposition rating of 4 indicated that this composition was unacceptable and measurably inferior to the formulation of this invention embodied, for example, in Example C.

Other suitable compositions of this invention are:

EXAMPLE E Pentasodium salt of benzene pentacarboxylic acid 15.071 Hexasodium salt of benzene hexacarboxylic acid 7.571 3-(N,N-dimethyl-N-hexadecyl-ammonio)-2- 45.071 hydroxypropanel sulfonate Sodium silicate (SiO ,:Na-,O ratio 2.0) 10.0% Sodium sulfate 7,57: Water 15.0%

EXAMPLE F Pcntasodium salt of benzene pentacarboxylic acid 5.07: Hexasodium salt of benzene hexacarboxylic acid 50.07: Sodium tallow soap 5.5% Sodium silicate (siO- zNa O ratio 2.0) l6.0'7r Sodium sulfate l3.5'71 Water EXAMPLE G Pentasodium salt of benzene pentacarboxylic acid 2.0% Hcxasodium salt of benzene hexacarboxylic acid 10.09: TE;,S (as in Example C) 60.0% Sodium Silicate (SiO-,:Na O ratio 2.0) 8.0% Sodium sulfate 10.0% Water 10.0%

EXAMPLE H Pentasodium salt of benzene pentacurhoxylic acid 150% Hexasodium salt of benzene hexacurboxylic acid 45.07! Sodium B-methoxy hexadecane sullonate 3.0% Sodium silicate (SiO,:Nu O ratio 21)) 10.071 Sodium sulfate 10.0% Water 17.0%

What is claimed is: 1. A built detergent composition consisting essentially of:

a. an organic water-soluble synthetic detergent selected from the group consisting of anionic, nonthe detergency builder is from 5:1 to 1:20. 

1. A BUILT DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF: A. AN ORGANIC WATER-SOLUBLE SYNTHETIC DETERGENT SELECTED FROM THE GROUP CONSISTING OF ANIONIC, NONIONIC, ZWITTERIONIC AND AMPHOLYTIC DETERGENTS, OR MIXTURES THEREOF; AND B. AS A DETERGENCY BUILDER, THE BIODEGRADABLE PHOSPHORUSFREE, WATER-SOLUBLE SALTS OF A MIXTURE OF BENZENE PENTACARBOXYLIC ACID AND BENZENE HEXACARBOXYLIC ACID IN THE PROPORTION BY WEIGHT OF 1:1, RESPECTIVELY, THE CATION FORMING THE WATERSOLUBLE SATLS OF SAID CARBOXYLIC ACIDS BEING SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL, AMMONIUM OR TETRAALKYLAMMONIUM IN WHICH THE ALKYL GROUP IN METHYL, ETHYL, PROPYL OR ISOPROPYL, AND WHEREIN THE PROPORTION BY WEIGHT OF THE DETERGENT TO THE DETERGENCY BUILDER IS FROM 5:1 TO 1:20. 